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CFM's

Whats the Minimum CFM's for exhaust when balancing a EVR/HRV I know the amount is determined by the number of exhaust point divided by the total amount of CFM's of the unit i.e 200/6= 33.3 cfm per exhaust point but how low of CFM's would be allowable where you would still have proper ventilation ?

So if my house for sake of argument needs 200 cfm's and I install 10 exhaust points with each point of exhaust having only 20 CFM's that would be sufficient even if one or more of the rooms was 400 sq. ft. ?

Whats the Minimum CFM's for exhaust when balancing a EVR/HRV I know the amount is determined by the number of exhaust point divided by the total amount of CFM's of the unit i.e 200/6= 33.3 cfm per exhaust point but how low of CFM's would be allowable where you would still have proper ventilation ?

I can't say I've ever used that formula.
As beenthere says, it depends on what the house needs.
It also depends on what the requirement of each exhaust point is.
For instance, a large kitchen would require more ventilation than a powder room.
The HRV ductwork should be sized and installed accordingly.

So if my house for sake of argument needs 200 cfm's and I install 10 exhaust points with each point of exhaust having only 20 CFM's that would be sufficient even if one or more of the rooms was 400 sq. ft. ?

200 cfm might be 2 or 3 times more than typcially needed for continuous ventilation. See ASHRAE 62.2

Designer Dan
It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE
Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

200 cfm might be 2 or 3 times more than typcially needed for continuous ventilation. See ASHRAE 62.2

Good point.
I haven't seen ASHRAE 62.2.
But, I seldom see anyone operate their HRV continuously.
Around here, they are used as glorified exhaust fans.
Therefore, we size them to maximum exhaust capability.

200 cfm might be 2 or 3 times more than typcially needed for continuous ventilation. See ASHRAE 62.2

I'm not sure if 200CFMs would be too much or just boarder line since both me and the wife are smokers thou it's mostly contained in the main living area and do not smoke upstairs in the sleeping area of the home. I was thinking the Renewaire EV-200 would be just a tad much but am rethinking maybe going with the EV-130 and I am going to operate the unit continuiously and would possibly have the baths connected thou here again I'm thinking of running the baths on a seprate inline fan along with the Kitchen exhaust so I'm still pndering just how to set-this all up.

If I lose the inline fan idea and run everything thru the EV 130 or 200 and use the inline fan for just the kitchen exhaust so I guess it all depends on which is my best option but am open to suggestion .....

Dang - Pollution control is not my fortay

Originally Posted by DanW13

I'm not sure if 200CFMs would be too much or just boarder line since both me and the wife are smokers thou it's mostly contained in the main living area and do not smoke upstairs in the sleeping area of the home. I was thinking the Renewaire EV-200 would be just a tad much but ...